The present invention relates to amines or salts thereof, which are useful as catalyst and the like, and to methods of preparing the amines or the salts.
Of amines, for example, metal salts of sulfonylamines and hydrates of these salts are disclosed in Japanese Patent Unexamined Publication JP-A-Hei-7-246338. These compounds disclosed therein are usable as Lewis acid catalysts and represented by the following general formula of M[RfSO2xe2x80x94Nxe2x80x94SO2Rfxe2x80x2]n or of M[RfSO2xe2x80x94Nxe2x80x94SO2Rf xe2x80x2]nxc2x7mH2O wherein Rf and Rfxe2x80x2 each represent perfluoroalkyl groups having a carbon atom number from 1 to 8, M represents a positive ion selected from a special group disclosed therein, n represents an integer that is the same as the valence of M, and m represents a natural number from 0.5 to 20.
Argyropoulos et al. Journal of Applied Polymer Science, Vol. 26, 3073-3084 (1981) discloses, as another example of amines, bis(ethoxysulfonyl)amine, HN(C2H5OSO2)2, and polysulfonylamine.
It is an object of the present invention to provide a novel amine or its salt, which has a fluorocarbon sulfonic acid ester group, and a method of preparing the amine or its salt.
According to the present invention, there is provided a novel first compound which is one of a first amine and a first salt of the first amine. This first compound has a fluorocarbon sulfonic acid ester group, and is represented by the general formula (1) (thus hereinafter referred to as xe2x80x9cthe first compound (1)xe2x80x9d, xe2x80x9cthe first amine (1)xe2x80x9d, or xe2x80x9cthe first salt (1)xe2x80x9d):
M[Rf1OSO2NSO2ORf2]nxe2x80x83xe2x80x83(1) 
wherein Rf1 and Rf2 represent the same or different fluorine-containing monovalent organic groups each of which has a carbon atom number from 2 to 18, a straight-chain portion, a branched-chain portion and/or a ring chain portion, and an optional unsaturated bond and an optional oxygen atom; M represents a positive ion which has a first valence and is one selected from the group consisting of hydrogen ion, ammonium ion, quaternary ammonium ions, alkali metal ions, alkali earth metal ions, transition metal ions, rare earth element ions, aluminum ions, gallium ions, iridium ions, thallium ions, tin ions, lead ions, arsenic ions, antimony ions, and bismuth ions; and n represents an integer that is the same as the first valence.
According to the present invention, there is provided a first method of preparing the first compound (1). This first method comprises the step of:
(a) reacting bis(chlorosulfonyl)amine represented by the formula (2) (hereinafter referred to as xe2x80x9cthe bis(chlorosulfonyl)amine (2)xe2x80x9d) with a fluoroalcohol represented by the general formula (3) (hereinafter referred to as xe2x80x9cthe fluoroalcohol (3)xe2x80x9d), so as to prepare the first amine (1) wherein M represents a hydrogen ion, and n is 1,
HN(SO2Cl)2xe2x80x83xe2x80x83(2) 
Rf3OHxe2x80x83xe2x80x83(3) 
wherein Rf3 represents the same or different groups which are identical with the Rf1 and the Rf2.
According to the present invention, there is provided a novel second compound which is one of a second amine and a second salt of the second amine. This second compound has a fluorocarbon sulfonic acid ester group, and is represented by the general formula (4) (thus hereinafter referred to as xe2x80x9cthe second compound (4)xe2x80x9d, xe2x80x9cthe second amine (4)xe2x80x9d, or xe2x80x9cthe second salt (4)):
xe2x80x94[M[Nxe2x80x94SO2ORf4OSO2]n]mxe2x80x94xe2x80x83xe2x80x83(4) 
wherein Rf4 represents a fluorine-containing bivalent organic group which has a carbon atom number from 3 to 18, a straight-chain portion, a branched-chain portion and/or a ring chain portion, and an optional unsaturated bond and an optional oxygen atom; M represents a positive ion as defined above; n represents an integer as defined above, and m represents an integer from 1 to 1,000.
According to the present invention, there is provided a second method of preparing the second compound (4). The second method comprises the step of:
(b) reacting bis(chlorosulfonyl)amine (2) with a fluorodiol represented by the general formula (5) (hereinafter referred to as xe2x80x9cthe fluorodiol (5)xe2x80x9d), so as to prepare the second amine (4) wherein M is a hydrogen ion, and n is 1,
HORf5OHxe2x80x83xe2x80x83(5) 
wherein Rf5 represents a bivalent organic group which is identical with Rf4.
In the invention, the above-mentioned first method further optionally comprises, after the step (a), the step of: (c) reacting the first amine (1) with a third compound, so as to prepare the first salt (1), the third compound being one selected from the group consisting of ammonia, quaternary ammonium compounds, hydroxides of an element, oxides of the element, carbonates of the element, halides of the element, fluorides of the element, chlorides of the element, bromides of the element, iodides of the element, and acetates of the element, the element being one selected from the group consisting of alkali metals, alkali earth metals, transition metals, rare earth elements, aluminum, gallium, iridium, thallium, tin, lead, arsenic, antimony, and bismuth.
In the invention, the above-mentioned second method further optionally comprises, after the step (b), the step of: (d) reacting the second amine (4) with the above-mentioned third compound, so as to prepare the second salt (4).
Similar to the above-mentioned conventional metal salts of sulfonylamines and hydrates of these metal salts, the first and second compounds (1) and (4) according to the present invention have fluorine-containing amine ions. These amine ions are stabilized by a strong electron attractive force of the fluorine atoms. Thus, the ionic bond between the fluorine-containing amine ions and the positive ions becomes small. With this, the first and second compounds (1) and (4) have large dissociation constants. Therefore, these compounds (1) and (4) are fully expected to be usable as a catalyst and the like, in the synthesis of organic compounds.
A novel first compound (1) according to the present invention is represented by the general formula (1):
M[Rf1OSO2NSO2ORf2]nxe2x80x83xe2x80x83(1) 
wherein Rf1 and Rf2 represent the same or different fluorine-containing monovalent organic groups. Examples of these groups are fluorine-containing straight chain or branched chain alkyl and alkenyl groups each having a carbon atom number from 2 to 18, fluorine-containing cycloalkyl and cycloalkenyl groups each having a carbon atom number from 3 to 18, fluorine-containing aryl groups each having a carbon atom number from 6 to 18, and mixtures thereof. Preferable examples of Rf1 and Rf2 are fluoroalkyl groups represented by RfCH2xe2x80x94 and (Rf)2CHxe2x80x94 where Rf is a fluoroalkyl group having a carbon atom number from 1 to 8.
Preferable examples of the positive ion represented by M in the general formula (1) are hydrogen ion, ammonium ion, quaternary ammonium ions, alkali metal ions, alkali earth metal ions, transition metal ions, and rare earth element ions.
The first compound (1) has the following six exemplary structures. 
The above-mentioned bis(chlorosulfonyl)amine (2) used for preparing the first amine (1) can be synthesized, for example, by a method disclosed in Inorganic Syntheses, Vol. VIII, 1966, pp. 105-107, using phosphorus(V) chloride, sulfonic acid amide, and chlorosulfonic acid.
Preferable examples of the above-mentioned fluoroalcohol (3) used for preparing the first amine (1) are RfCH2OH and (Rf)2CHOH where Rf represents a fluoroalkyl group having a carbon atom number from 1 to 8, such as 2,2,2-trifluoroethylalcohol (CF3CH2OH), 2,2,3,3,3-pentafluoropropanol (CF3CF2CH2OH), 1,1,1,3,3,3-hexafluoro-2-propanol ((CF3)2CHOH), and 2,2,3,3-tetrafluoropropanol (CF2HCF2CH2OH).
In the step (a) of the above-mentioned first method, bis(chlorosulfonyl)amine (2) is reacted with the fluoroalcohol (3), in a solvent or without using solvent, for preparing the first amine (1). In order to obtain a higher yield, it is preferable to react 1 part by mol of bis(chlorosulfonyl)amine (2) with 2 parts by mol of the fluoroalcohol (3). This reaction is expressed as the following reaction formula (1).
HN(SO2Cl)2+2Rf3OH)xe2x86x92HN(SO2ORf3)2+2HClxe2x80x83xe2x80x83(1) 
In the step (a), Rf1 and Rf2 of the first amine (1) become different groups by at first reacting one type of the fluoroalcohol (3) with an excessive amount of the bis(chlorosulfonyl)amine (2) so as to produce HN(SO2ORf3)(SO2Cl), and then by reacting this product with another type of the fluoroalcohol (3).
The step (a) is conducted preferably at a temperature within a range from about 0xc2x0 C. to about 200xc2x0 C. and more preferably at a temperature within a range from 40xc2x0 C. to 100xc2x0 C. If it is lower than about 0xc2x0 C., the reaction rate becomes substantially slow. If it is higher than about 200xc2x0 C., the raw materials of the reaction, the solvent if used, and the reaction product may be decomposed.
In the step (a), it is possible to use a solvent not limited to a particular type, as long as it is inert in the reaction. Examples of this solvent are halogenated hydrocarbons such as methylene chloride, ethylene chloride and perfluorocarbons; hydrocarbons such as benzene, heptane and cyclohexane; ethers such as diethyl ether, diisopropyl ether and dioxane; and nitrites such as acetonitrile.
In the step (a), the reaction product (i.e., the first amine (1)) can be obtained as a fluoroalkoxy-sulfonylamine by removing the solvent after the reaction, through evaporation or distillation. The thus obtained reaction product can be purified through sublimation under reduced pressure or through recrystallization.
For example, the first salt (1), that is, the ammonium salt of the first amine (1), is obtained in the above-mentioned step (c) of the first method, when the first amine (1) is reacted with ammonia (i.e., the third compound). Furthermore, the first salt (1), that is, the quaternary ammonium salt of the first amine (1), is obtained in the step (c), when the first amine (1) is reacted with a substitution compound of ammonia. Examples of this substitution compound are primary, secondary and tertiary amines such as methylamine, diethylamine and triethylamine, heterocyclic amines such as pyridine and piperidine, aromatic amines such as aniline, quaternary ammonium halides such as tetraethylammonium fluoride, and quaternary ammonium hydroxides such as tetraethylammonium hydroxide. Still furthermore, the first salt (1) other than the above-mentioned types is obtained in the step (c), when the first amine (1) is reacted with a hydroxide of an element, an oxide of this element, a carbonate of this element, halides of this element, fluorides of this element, chlorides of this element, bromides of this element, iodides of this element, or an acetate of this element. This element is one selected from the group consisting of alkali metals (e.g., lithium, sodium and potassium), alkali earth metals (e.g., magnesium and calcium), transition metals (e.g., titanium, vanadium, manganese, cobalt, nickel, copper, silver, zinc and cadmium), rare earth elements (e.g., lanthanum), aluminum, gallium, iridium, thallium, tin, lead, arsenic, antimony, and bismuth.
As is mentioned above, the second compound (4), an fluoroalkoxysulfonylamine polymer, is represented by the general formula (4):
xe2x80x94[M[Nxe2x80x94SO2ORf4OSO2]n]mxe2x80x94xe2x80x83xe2x80x83(4) 
wherein Rf4 represents a fluorine-containing bivalent organic group. Examples of this group are fluorine-containing straight chain or branched chain alkylene and alkenylene groups each having a carbon atom number from 3 to 18, fluorine-containing cycloalkylene and cyclo-alkenylene groups each having a carbon atom number from 3 to 18, fluorine-containing arylene groups each having a carbon atom number from 6 to 18, and mixtures thereof.
Preferable examples of Rf4 are fluoroalkylene groups represented by xe2x80x94CH2RfCH2xe2x80x94where Rf is a fluoroalkylene group having a carbon atom number from 1 to 8. Examples of the second compound (4) are polymeric[(polyfluoroalkoxy)sulfonyl]amine, xe2x80x94[HNxe2x80x94SO2OCH2(CF2)4CH2OSO2]mxe2x80x94, and lithium salt of polymeric[(polyfluoroalkoxy)sulfonyl]amine, xe2x80x94[LiNxe2x80x94SO2OCH2(CF2)4CH2OSO2]mxe2x80x94.
In the step (b) of the above-mentioned second method, bis(chlorosulfonyl)amine (2) is reacted with the fluorodiol (5), in a solvent or without using solvent, so as to prepare the second amine (4). Carbon atom(s) in the group of Rf5 in the general formula (5), each of the carbon atom(s) is directly bonded to oxygen atom, is preferably not directly bonded to fluorine atom(s). An example of the fluorodiol (5) is HOCH2(CF2)nCH2OH where n is an integer from 1 to 8.
The molecular weight of the second amine (4) can be controlled by adjusting the reaction condition of the step (b). In other words, it can be controlled, for example, by adjusting the reaction temperature, or by selecting a suitable solvent among solvents different in polarity. The reaction in the step (b) is expressed as the following reaction formula (2).
mHN(SO2Cl)2+mHORf5OHxe2x86x92xe2x80x94[HNxe2x80x94SO2ORf5OSO2]mxe2x80x94+2mHClxe2x80x83xe2x80x83(2) 
The step (b) is conducted preferably at a temperature within a range from about 10xc2x0 C. to about 200xc2x0 C. If it is lower than about 0xc2x0 C., the reaction rate becomes substantially slow. If it is higher than about 200xc2x0 C., the raw materials of the reaction, the solvent if used, and the reaction product may be decomposed.
In the step (b), it is possible to use a solvent not limited to a particular type, as long as it is inert in the reaction. Examples of this solvent are the same as those of the solvent usable in the step (a).
In the step (b), the reaction product (i.e., the second amine (2)) can be obtained as an fluoroalkoxy-sulfonylamine polymer, by filtering precipitate out of the reaction solution, and then by removing the solvent from the precipitate through evaporation or distillation.
Similar to the step (c), the second salt (4) of the second amine (4) is obtained in the above-mentioned step (d) of the second method, when the second amine (4) is reacted with ammonia, the above-mentioned quaternary ammonium compound, a hydroxide of the above-mentioned element, an oxide of the element, a carbonate of the element, a halide of the element, a fluoride of the element, a chloride of the element, a bromide of the element, an iodide of the element, or an acetate of the element.
The following examples are illustrative of the present invention, but these examples are not limitative.